<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>演示JS</title>
</head>
<body>
    <script>
        let obj = {}
        const obj2 = {}

        obj.a = 10
        console.log(obj)
        obj.a = true
        console.log(obj)

        Object.assign(obj2,obj)
        console.log(obj2)
        let arr = []
        console.log(arr)
        let arr1 = new Array()
        console.log(arr)
        arr[0] = 'xxxx'
        console.log(arr)
        
    </script>
</body>
</html>